Immunoglobulin G4-related Coronary Periarteritis in a Patient Presenting with Myocardial Ischemia

Recent studies suggest that the cardiovascular system might be a possible target of immunoglobulin G4-related disease. Here we present a 66-year-old man who was admitted to our hospital because of chest symptoms suggestive of acute coronary syndrome. Besides luminal narrowing of the coronary arteries, marked periarterial thickening around the coronary artery was observed by computed tomography coronary angiography. Serum immunoglobulin G4 levels of this patient were elevated (564 mg/dL). The patient underwent coronary bypass surgery. After incision of the pericardium, a glittery white-yellowish, elastic-hard periarterial mass surrounding the left circumflex artery could be seen. Histologic analysis of the biopsy specimen showed the formation of lymphoid follicles and the presence of immunoglobulin G4-positive plasma cells; therefore, the diagnosis was immunoglobulin G4-related coronary periarteritis accompanied by physiologically significant myocardial ischemia.